Hypervelocity Drag
Based on Trajectory Optimization for an Apollo-type Vehicle under Entry Conditions Encountered During Lunar Returm by John W. Young (famous astronaut) and Robert E. Smith Jr., May 1967, NASA TR-R-258, Langley Research Center.
Equations on Page 5 in Foot-second-slug-BTU :
1a: \dot Q_c = 20 \sqrt{ \rho } ( V / 1000 )^3^ Btu/ft2-s
1b: \dot Q_r = 6.1 \rho^{3/2} ( V / 10 000 )^20^ Btu/ft2-s
Density in slugs/ft3: multiply kg/m3 by ......
Power in Btu/ft2-s: multiply by ..... to get W/m2
Velocity in ft/s: divide m/s by 0.3048
Metric equations: